In 2010, Dominic Cooper made a big splash opposite Carey Mulligan in the Oscar-nominated An Education. The role showed off his suave, dapper side, but in his latest film, the Sundance debut The Devil’s Double, Cooper really sinks his teeth into a role (or in this case, roles) and pushes himself to the extreme.

The Devil’s Double tells the story of Latif Yahia, an Iraqi military officer recruited to become the fiday, or body double, of Saddam Hussein’s tyrannical son Uday. Cooper plays two distinct roles in the film: the conflicted Latif, who struggles to take on his new job, and the murderous party animal Uday. The film is insane, to put it lightly, and the crazed tone is in part to Cooper’s disappearance into the two men’s stranger-than-fiction world.

The Devil’s Double is a wild ride and a real departure from previous work? How did you get involved with the film?

I read it, with the understanding that someone else had the part that it might fall through. I read it knowing that it had been around for many, many years, many directors had been attached, It was a script that stuck in my head. I was fascinated by how little I knew of something that affected so much of my life and the world, and ultimately, it was this mad gangster movie and the opportunity for an actor to play both those roles.

I was unsure about the person I heard doing the part at the time, it didn’t make sense to me. I managed to get into a room with Lee [Tamahori, director] and I auditioned for hours with him. I brought into the room something I thought this person was and who the other person was, and next thing I knew…I was doing it. It was the most exciting moment in the work I’ve done so far.

Were there resources to help you better understand how this world operated? To give insight into living out both Latif and Uday’s lives?

No, there was nothing to like that. The difficulty for me was to understand and have compassion for this person, which I think you have to do when you’re playing someone. When you’re inhabiting someone, looking through their eyes and understanding their complexities.

With this guy, I couldn’t. I couldn’t understand him – he was a madman, a berserk man that needed help. Everything he did was disgusting and atrocious. It wasn’t necessarily about him, they became more fictional characters. I think that was important for me and Lee both to kind and reach a point and use this as an incredible story but we don’t know what they said we don’t know the relationship they had. We’re making a film. And this is not meant to be stooped in the real truth. Lee said the only truth in this film is that the US got him. That’s the one fact that we know of this story.

That’s evident in the film. You’re constantly wondering what’s real because the tone jumps from gritty realism to over-the-top, often comedic levels. Uday is executing these insane operations and one minute you’re laughing, the next, you’re horrified. How did you balance the tones of the film?

That’s why you need to be in the hands of a genius like Lee, with this kind of material. An actor doesn’t know that. That’s why I have to rely on him for the tone and sensibility of the piece. I don’t know what he’s going for. I can kind of get a vague understanding. I didn’t know he was making a outrageous, horrific gangster film. What I knew is that he made the most stunning debut film with Once Were Warriors, and I knew that, if any one can handle that kind of material and those people, and can understand how those gangsters type tribal people. then he is the person to do it. And my job is to come up with something that fitted with that environment. And although sometimes humorous because you’re so baffled and amazed that this human exists.

Were there moments where you wanted to pull back but Lee pushed you to go further?

I think it was a matter of bringing it down. He kept me very still, that was very helpful. It was his actual energy on set that was so inspiring. It was a short shoot, relatively cheap, and we had a lot to do. Technically it was difficult because of the doubling up of the scenes.

What was the process of shooting two roles in one scene? Were you constantly repeating the setups and blocking?

Yes, and that was why you only really got three takes on anything. Some people like to go on and do take after take, I couldn’t do that. There wasn’t time. It wasn’t stressful, I loved it. And you watched him and he had to create a new environment. It would be like…Lee wasn’t allowed to use this position or camera angle. And he was completely reconfiguring his ideas and I always think that creates the most creative inspired work and its constantly moving. Watching him with the amount of decisions he had to make, [laughs] I kind of felt my job is kind of easy.

What challenges did you face embodying two separate roles, bouncing between characters on a whim?

I needed to make one who is watching it believe it is two different people no matter how much reconstructive surgery one of them had had and how much they needed to look the same which they did, it was difficult to decide who was who. I needed them to be clearly two different people, I got help from my wonderful dialect coach, I got help with the make-up lady. It was about making a vocal difference and physical difference and the way in which the two characters thought differently.

Into the film, you slowly realize there’s a third character you’re playing. Was that intentional?

Oh, definitely. The one that Latif had to transform into. I wanted here to be an intricate difference in the way he went to perform as Uday. I wanted him to be slightly different still. Not quite succeeding whole heartily in becoming him – there was still something holding him back. That’s why when you see him practicing in the mirror there’s still this tentativeness about him. He was not a showman, not an actor. There was no reason he should have been able to manipulate who he is. He did it to the best of his ability and I needed that to be clear.